diff --git a/addons/mass_mailing/static/src/scss/mass_mailing.scss b/addons/mass_mailing/static/src/scss/mass_mailing.scss
index 1ffec4fb499..b3146a7d1c0 100644
--- a/addons/mass_mailing/static/src/scss/mass_mailing.scss
+++ b/addons/mass_mailing/static/src/scss/mass_mailing.scss
@@ -87,7 +87,7 @@
     }
 }
 
-.o_kanban_view {
+.o_kanban_renderer, .o_legacy_kanban_view {
     .oe_kanban_mass_mailing {
         .o_title {
             margin-bottom: 16px;
@@ -104,16 +104,17 @@
     }
     &.o_kanban_mailing_list {
         .o_kanban_group:not(.o_column_folded) {
-            width: 350px + $o-kanban-group-padding;
-        }
-        .o_kanban_record {
-            width: 350px;
+            flex-basis: 380px
         }
         &.o_kanban_ungrouped {
             padding: 0;
             .o_mailing_list_kanban_grouped {
                 display: none !important;
             }
+            .o_kanban_record {
+                width: 100%;
+                margin: 0;
+            }
         }
         &.o_kanban_grouped .o_mailing_list_kanban_ungrouped {
             display: none !important;
diff --git a/addons/mass_mailing/views/mailing_list_views.xml b/addons/mass_mailing/views/mailing_list_views.xml
index 22de8850c81..4fa092a37d7 100644
--- a/addons/mass_mailing/views/mailing_list_views.xml
+++ b/addons/mass_mailing/views/mailing_list_views.xml
@@ -150,8 +150,7 @@
                                 <div class="d-flex align-items-center">
                                     <div class="mr-3">
                                         <button class="btn btn-primary" name="action_view_contacts" type="object">
-                                            <t t-esc="record.contact_count.value"/>
-                                            <span>Contacts</span>
+                                            <t t-esc="record.contact_count.value"/> <span>Contacts</span>
                                         </button>
                                     </div>
                                     <div class="flex-grow-1 d-flex flex-column align-items-end o_mass_mailing_kanban_contact_links">
@@ -194,7 +193,7 @@
                             </div>
                         </div>
                         <!-- Card when the Kanban view is not grouped -->
-                        <div class="oe_kanban_global_click o_mailing_list_kanban_ungrouped w-100 m-0 d-flex flex-row justify-content-between align-items-center flex-wrap">
+                        <div class="oe_kanban_global_click o_mailing_list_kanban_ungrouped d-flex flex-row justify-content-between align-items-center flex-wrap">
                             <div class="col-lg-3 col-sm-6 col-12 py-0 my-auto">
                                 <div class="d-flex text-large">
                                     <span class="d-inline-block text-truncate font-weight-normal text-large"